I beat it using save states after each "stage" (stage in quotes, as it doesn't announce each one, immediately going to the next one after each boss).
Even though this is on the PC Engine part of the TG-16 Mini, I believe meaning those games are the Japanese releases, what little text is all in English.
I would have really liked this if not for losing all power-ups when you get hit and die -- and you only get one hit. Because of this, with very few exceptions of where you die, you might as well restart the game whenever you die. Unless you put in way more effort than I'm willing to do, it's extremely difficult to survive pretty much any stretch after the beginning of the game with no power-ups (or being able to speed up once if you had collected at least one power capsule when you died) while rebuilding those power-ups. With a decent amount of power-ups, the game is manageable.
The convention of having to store up power capsules to get certain power-ups, as opposed to having different types of power-ups to collect, is a nice change. I like the power-up of having up to four indestructible spheres that fire the same weapons as your ship, although along with the front shield power-up, I tend to lose focus on where my actual ship is.
The game has massive slow down in many places with the amount of enemies and projectiles that are on-screen. It would be nice if the "stage" bosses weren't all the exact same with the same pattern, with the exception of the end "boss" that probably takes effort to die against. The wave of enemies right before the boss shows up is also disappointing in that just about all of them are survivable by simply staying in one spot while constantly firing. After you beat the game, it restarts with the difficulty increased -- I did make it to the end on the 2nd stage and the enemies do actually fire at you, rather than simply rushing at you, before quitting.
